The invention relates to firearms.
The invention has utility as an automatic, high rate of fire, firearm whereby it may be used for example, as a close-in ship-board defense against bombs, missiles or attack aircraft for launching large numbers of projectiles within a short period of time. The invention also has utility in hand guns such as a rapid fire pistol or rifle which may be disposable.
Currently, most firearms use cartridge ammunition which is mechanically fed to a barrel. Such firearms have numerous moving parts, tend to be heavy and complex, may jamb or be unreliable, and require elaborate delivery and loading systems to support the rate of fire. The rate of fire of automatic firearms of this type is limited by the time required to load the cartridge, seal the barrel, unseal the barrel and eject the empty case.
More recently, firearms have begun to utilise caseless ammunition which obviates the need to eject an empty case subsequent to firing. However, these firearms retain many of the problems of conventional firearms.
The present invention aims to provide an alternative barrel assembly for a firearms system which will alleviate at least one of the disadvantages of the prior art.
In particular, the present invention aims to provide a barrel assembly including projectiles axially stacked in a barrel, wherein the projectiles are of the type having a head portion and an integral trailing cylindrical portion whereby the projectiles may be expanded into sealing engagement with the barrel.
According to one aspect this invention provides a barrel assembly for firearms, said barrel assembly including:
a barrel;
a plurality of projectile assemblies axially disposed in end to end abutting relationship within said barrel for operative sealing engagement with the bore of the barrel, each projectile assembly including a projectile head and an integral cylindrical spacer portion extending axially and rearwardly from said projectile head;
discrete propellant charges accomodated within said cylindrical spacer portion for propelling respective projectile assemblies sequentially through the muzzle of the barrel;
ignition means for igniting said discrete propellant charges; and
control means for selectively and sequentially actuating the ignition means.
The rearward end of the cylindrical spacer portion is preferably adapted to abut the forward or leading end of the subsequent projectile assembly. The cylindrical spacer portion may be expanded into operative sealing contact with said bore of the barrel. Suitably, the interior of the cylindrical spacer portion is structurally reinforced to prevent excessive radial expansion. Desirably, the trailing cylindrical extension of the projectile extends in close proximity with the barrel.
According to a further aspect, this invention provides a barrel assembly for firearms, said barrel assembly including:
a barrel having a muzzle;
a plurality of projectiles axially disposed in end to end abutting relationship within said barrel, each projectile including a projectile head and a trailing cylindrical extension in close proximity with the barrel;
an internal wedging surface, at or adjacent the trailing end of said cylindrical extension which accommodates a tapered nose part of the following projectile, for expanding said trailing end into enhanced sealing engagement with the barrel upon engagement of said wedging surface with said tapered nose part;
discrete propellant charges for propelling respective projectiles sequentially through the muzzle of said barrel;
ignition means disposed externally of the barrel for igniting said discrete propellant charges; and
control means for selectively and sequentially actuating said ignition means.
The trailing cylindrical extension may at least partly define a propellant space therein. Alternatively the propellant charges may surround the noses of respective following projectiles externally of the trailing cylindrical extension.
Each projectile may include an internal spacer which extends through the trailing cylindrical extension from the projectile head to abut or cooperate with the inserted projectile head of a following projectile whereby axial compressive loads applied to a stack of projectiles arranged in sealing engagement within a barrel may be resisted through abutting projectiles. Alternatively such loads may be distributed back to the barrel from individual projectiles through their engagement with the barrel.
The spacer may include support for the trailing cylindrical extension which may be a thin cylindrical rear extension of the projectile head. The spacer may be integral with the head and trailing cylindrical extension or it may be formed separately therefrom and from a different material if required.
In such arrangements the projectile head and spacer may be loaded into the barrel and thereafter an axial displacement thereof caused to expand the trailing end and enhance the sealing engagement between the projectiles and the barrel. This axial displacement is suitably caused individually as the projectiles are subsequently loaded into the barrel. The radial expansion into enhanced sealing engagement with the barrel may be limited through engagement between the penetrating nose of a following projectile and the internal spacer assembly.
The ignition means may be electrical, chemical, mechanical or any other conventional primer. Conveniently, the ignition means is electrical and the control means is an electrical control adapted to provide electrical ignition pulse to the respective ignition means. Suitably the control means is configured to enable a user to selectively control the rate, number, and frequency of the pulses to provide a desired firing pattern. The control means may fire the projectile assemblies singly, in pairs, or in any other combinations.
The projectile assembly may be round, conventionally shaped or dart-like and the fins thereof may be off-set to generate a stabilising spin as the dart is propelled from a barrel which may be a smooth-bored barrel. In addition the barrel assembly may find utility as a removable/replaceable barrel of a rifle or pistol.
Alternatively the barrel assembly constitutes one of a plurality of barrel assemblies and the control means may actuate the ignition means of each of the barrel assemblies in such manner that a sequential plurality of arrays of projectile assemblies are propelled in following relationship. Aiming and firing of the arrays of projectile assemblies may be controlled by a conventional radar fire control system or other known fire control systems. The individual barrel assemblies may be aimed such that the array of projectile assemblies converges at a particular range to give a maximum density of projectile assemblies at that range.
Alternatively, the array of projectile assemblies may diverge to maximise coverage of an area. Thus, the average separation distance at the target between the projectile assemblies in an array can be predetermined and adjusted to suit the nature and range of the target. Of course, the individual barrel assemblies may be fired randomly or independently of the other barrel assemblies.
The propelling charges may be either solid or granular and compression of either may be an undesirable, moreover, movement of the projectile assemblies relative to the barrel may cause misalignment of the ignition means with their respective propellant charges.
It is preferred that the ignition means be disposed at the leading end of the propellant charge so as to minimise possible energy loss in accelerating the front portion of the propellant charge.
In another embodiment, complementary wedging surfaces are disposed on the spacer assembly and projectile head respectively whereby the projectile head is urged into engagement with the bore of the barrel in response to relative axial compression between the spacer means and the projectile head. In such arrangement the projectile head and spacer assembly may be loaded into the barrel and thereafter an axial displacement is caused to ensure good sealing between the projectile head and barrel. Suitably the extension means is urged into engagement with the bore of the barrel.
Preferably, the projectile head defines a tapered aperture at its rearward end into which is received a complementary tapered spigot disposed on the leading end of the spacer assembly, wherein relative axial movement between the projectile head and the complementary tapered spigot causes a radially expanding force to be applied to the projectile head.
The barrel may be non-metallic and the bore of the barrel may include recesses which may fully or partly accommodate the ignition means. In this situation the barrel houses electrical conductors which facilitate electrical communication between the control means and ignition means. This arrangement may be utilised for disposable barrel assemblies which have a limited firing life and the ignition means and control wire or wires therefor can be integrally manufactured with the barrel.
In an alternative arrangement, a barrel assembly includes ignition apertures in the barrel and the ignition means are disposed outside the barrel and adjacent the apertures. The barrel may be surrounded by a non-metallic outer barrel which may include recesses adapted to accommodate the ignition means. The outer barrel may also house electrical conductors which facilitate electrical communication between the control means and ignition means. The outer barrel may be formed as a laminated plastics barrel which may include a printed circuit laminate for the ignition means.
Both of the above arrangements lend themselves to a modular or disposable construction. The barrel assemblies may be adapted for firing as is, or may be adapted for mounting within a housing.
For safety, the barrel assembly may include an arming switch associated with each ignition means which is closed in response to the preceding projectile assembly being discharged. Preferably, the arming switch is closed by biasing means which are normally resisted by the preceding projectile assembly. In a preferred embodiment, the projectile head and spacer assembly each constitute switch contacts which are normally electrically isolated from each other and wherein an electrical circuit between the barrel and spacer body is completed in response to the preceding projectile assembly being discharged. In this arrangement, the barrel, which is in electrical contact with the projectile head, is also in contact with one of the electrodes.